Zwischenzug
A zwischenzug is an in-between move played before the expected recapture or reply.
What to look for
Before making the obvious move, check for a stronger check, capture, or threat first.
Recognize the mechanism
Pause before an expected recapture and consider a more urgent intermediate move. The key is move order: your new threat may change the terms of the exchange before you resume it.
Common practical mistake
An intermediate move must be strong enough to justify delaying the expected action. Verify whether the opponent can ignore it and keep the material.
Training goal
Train the habit of looking for forcing in-between moves.